The invention relates to a rubber mixture, in particular for the inner liner of pneumatic vehicle tires. Furthermore, the invention relates to a pneumatic vehicle tire with an inner liner which is based on such a rubber mixture. For reduced plasticizer diffusion along with good compressive and tensile properties, the rubber mixture contains a) 50-100 parts by weight of at least one halobutyl rubber, b) up to a maximum of 50 parts by weight of at least one further rubber, selected from the group comprising butyl rubber, polybutadiene, styrene-butadiene copolymer, 3,4-polyisoprene, cis-1,4-polyisoprene, natural rubber, styrene-isoprene copolymer and styrene-isoprene-butadiene terpolymer, the parts by weight of a) and b) adding up to 100, c) 5-45 parts by weight, based on 100 parts by weight of a) and b), of at least one polyisobutylene with a weight-average molecular weight Mw of over 400 000 g/mol and d) 10-120 parts by weight, based on 100 parts by weight of a) and b), of at least one carbon black.